ACCIONA has released a timelapse video showcasing six months of construction work to assemble one of two tunnel boring machines (TBMs) for the NSW Government’s Western Harbour Tunnel in Sydney, Australia.
The footage condenses the complex process of assembling the 120-metre-long machine inside one of two underground caverns at Birchgrove, each among the largest ever TBM and assembly chambers excavated in the world.
The first TBM, named Patyegarang, will excavate the 1.5-kilometre section of tunnel beneath Sydney Harbour, up to 50 metres below the harbour.
Precision engineering at scale
Andrew Marsonet, ACCIONA Project Director, Western Harbour Tunnel, said the video highlights the scale and precision involved in preparing the TBMs for their journey.
“The timelapse gives the public a rare insight into the engineering effort required to assemble these machines underground,” Mr Marsonet said.
“Every component, from the cutterhead to the trailing gear, must be installed in a precise sequence to ensure the TBM operates safely and efficiently once launched.”
Assembly by the numbers
The assembly process involves positioning 263 major components, supported by a 500-tonne gantry crane, within the cavern.
- 263 major components positioned during assembly
- 500-tonne gantry crane used within the cavern
- 4,350 tonnes per TBM — equivalent to 88 double-decker buses
Each TBM weighs 4,350 tonnes, equivalent to 88 double-decker buses, and both machines are currently operating around the clock.
Massive launch chambers at Birchgrove
The two launch chambers at Birchgrove, each 28 metres high and located just 230 metres from the harbour’s edge, were completed earlier this year.
Together, they are large enough to fit 22 Olympic swimming pools or six Emerald-class Sydney Ferries. These chambers serve as the launch point for the TBMs as they carve a route under Sydney Harbour from Birchgrove to Waverton.
Connecting Sydney's harbour crossings
When complete, Western Harbour Tunnel will provide a 6.5-kilometre connection between the Warringah Freeway near North Sydney and Rozelle, reducing congestion on the Sydney Harbour Bridge and Sydney Harbour Tunnel.
